Patient guide · Bone health
Bone densitometry (DEXA), the gold-standard scan for osteoporosis and fracture risk.
A dual-energy X-ray absorptiometry (DEXA) scan measures bone mineral density at the hip and lumbar spine — the gold-standard test for osteoporosis diagnosis, fracture risk and treatment monitoring.
Key facts
- 01
Definition
Dual-energy X-ray absorptiometry (DEXA) of the hip and lumbar spine.
- 02
Gold-standard
The reference test for osteoporosis diagnosis and fracture-risk stratification.
- 03
T-score thresholds
T-score ≤ -2.5 defines osteoporosis; -1.0 to -2.5 is osteopenia.
- 04
Integrates with FRAX
Feeds the FRAX calculator for a 10-year major-osteoporotic and hip-fracture risk.
- 05
Very low radiation dose
A fraction of a chest X-ray — comparable to a day of natural background radiation.
- 06
Guides therapy
Sets the threshold for treatment initiation and tracks response on repeat scanning.
Preparation and journey
From referral to report — what happens, in order.
A DEXA scan is quick, painless and needs almost no preparation. This is the whole journey, step by step.
Phase 1 · Before your scan
Referral and preparation
Phase 2 · On the day
~10 minutes at the clinic
Phase 3 · After
Report and next steps
- 01
Before
Referral
From your GP, rheumatology, endocrine or women’s health team — or by self-referral in most private clinics.
- 02
Before
No fasting required
Eat, drink and take medication as normal. Avoid calcium supplements for 24 hours if possible.
- 03
Before
Wear light clothing without metal
Zips, buckles, buttons and underwires interfere with the beam — a plain gown is often provided.
- 04
On the day
Lie on the scan bed
You lie flat on your back on a padded bed; the scanning arm moves slowly overhead.
- 05
On the day
Hip and lumbar spine scanned
Both regions are imaged in 5–10 minutes — painless, still, no injections.
- 06
On the day
Vertebral fracture assessment (optional)
A lateral spine image (VFA) can be added to detect silent compression fractures.
- 07
After
Report with T-score, Z-score and FRAX
A consultant-reported summary with numerical scores and a 10-year fracture-risk figure.
What it shows
What a DEXA scan can tell you.
DEXA answers a specific set of questions — bone density, fracture risk, and the response to treatment. These are the results your report will speak to.
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Osteoporosis
T-score ≤ -2.5 at the hip or lumbar spine.
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Osteopenia
T-score between -1.0 and -2.5 — a lower-than-normal bone density.
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Vertebral fracture on VFA
Silent compression fractures picked up on lateral spine imaging.
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Loss of height
Historic compression fractures suggested by measurable height loss.
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FRAX 10-year risk
Major-osteoporotic and hip-fracture probability over the next decade.
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Trabecular Bone Score (TBS)
A texture measure of the lumbar spine that adds independent fracture-risk information.
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Response to therapy
Change in bone density on a repeat scan, once treatment has been in place.
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Red flag: severe osteoporosis + fragility fracture — urgent fracture-liaison referral
Combined findings trigger urgent referral into a fracture-liaison service.
Next steps
Treatment options after a DEXA scan.
What your bone-health team is likely to consider — treatment is guided by your T-score, FRAX result, fracture history and personal risk.
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Lifestyle advice
Weight-bearing exercise, adequate calcium intake, vitamin D and smoking/alcohol modification.
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Bisphosphonates
First-line oral alendronate or intravenous zoledronate for most patients.
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Denosumab (Prolia)
Six-monthly subcutaneous injection when bisphosphonates aren’t tolerated or appropriate.
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Anabolic therapy
Teriparatide or romosozumab for severe osteoporosis or very high fracture risk.
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HRT for menopausal women
Considered for prevention in women with early or symptomatic menopause.
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Falls-prevention programme
Balance training, home hazard review and medication review to reduce fall risk.
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Fracture-liaison service referral
Structured secondary-prevention pathway after any fragility fracture.
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Repeat DEXA in 2–3 years
Interval scanning to monitor treatment response and re-baseline risk.
Red flags
When earlier or extra imaging is warranted.
Any of the following should prompt earlier DEXA, a repeat scan sooner than usual, or referral to a fracture-liaison or bone-health specialist.
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Fragility fracture
A fracture from a standing-height fall or lower — a defining event, whatever the T-score.
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Height loss > 4 cm
Suggests unrecognised vertebral compression fractures.
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Steroid-induced osteoporosis
Long-term oral glucocorticoid use accelerates bone loss and warrants earlier DEXA.
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Post-transplant bone disease
Solid-organ transplant recipients lose bone rapidly in the first year.
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Early menopause
Menopause before age 45 raises lifetime fracture risk.
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Hyperparathyroidism
Primary hyperparathyroidism causes cortical bone loss — DEXA guides surgical decisions.
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Chronic malabsorption
Coeliac, inflammatory bowel disease and post-bariatric surgery all deplete bone.
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Concomitant myeloma / bone metastases
Malignant bone disease is not osteoporosis — additional imaging is needed.
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Bone marrow oedema on MRI
May indicate an occult fracture; correlate with DEXA and consider fracture-liaison review.
Sources and clinical review
Where this guide draws from.
Reviewed by Pulse Atlas Editorial Board (). Published 2026-07-30. Next scheduled review 2027-07-30. Reading time approximately 6 minutes.
A quiet reminder
This is a patient guide — not a substitute for personalised medical advice.
Discuss your DEXA result with your GP or bone-health specialist before making treatment decisions.
- 01 Source
Royal Osteoporosis Society (National Osteoporosis Society). UK clinical guidance on the diagnosis and management of osteoporosis.
Royal Osteoporosis Society (National Osteoporosis Society). UK clinical guidance on the diagnosis and management of osteoporosis. - 02 Source
NICE. Bisphosphonates for treating osteoporosis (TA464).
NICE. Bisphosphonates for treating osteoporosis (TA464). - 03 Source
International Society for Clinical Densitometry. Official positions on adult DEXA.
International Society for Clinical Densitometry. Official positions on adult DEXA. - 04 Source
FRAX — Fracture Risk Assessment Tool. University of Sheffield.
FRAX — Fracture Risk Assessment Tool. University of Sheffield.
Frequently asked
Everything we get asked about DEXA.
Quick answers on scores, radiation, follow-up intervals, FRAX and how DEXA compares to other bone-density tests.
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What is a DEXA scan?
A dual-energy X-ray absorptiometry (DEXA) scan uses two low-dose X-ray beams to measure bone mineral density at the hip and lumbar spine. It is the gold-standard test for osteoporosis diagnosis, fracture risk and treatment monitoring.
-
What do the T-score and Z-score mean?
The T-score compares your bone density to a healthy young adult of the same sex. A T-score ≤ -2.5 defines osteoporosis; -1.0 to -2.5 is osteopenia. The Z-score compares you to age-matched peers and is used for younger adults and to flag secondary causes of bone loss.
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How much radiation is involved?
A DEXA scan uses a very low dose — a small fraction of a chest X-ray and comparable to a single day of natural background radiation. It is one of the lowest-dose X-ray tests in routine use.
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How is DEXA different from a Bindex scan?
DEXA measures bone mineral density directly at the hip and spine and is the reference standard. Bindex is a radiation-free pulse-echo ultrasound of the tibia — useful for screening in primary care, but does not replace DEXA for diagnosis or monitoring.
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How often should a DEXA be repeated?
For most patients on treatment or being watched for change, a repeat scan every 2–3 years is appropriate. Higher-risk situations — steroid therapy, post-transplant, rapid loss — may warrant earlier repeat scanning.
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What is FRAX and why does it matter?
FRAX is a validated calculator that combines your DEXA result with clinical risk factors to estimate your 10-year probability of a major osteoporotic fracture and a hip fracture. Treatment thresholds in UK guidance are based on FRAX, not the T-score alone.
Related tests
Looking for a different test?
-
Bindex bone density
Radiation-free pulse-echo ultrasound of the tibia — a primary-care screening alternative.
Learn more -
Body composition analysis
Fat, lean mass and visceral fat measurement — often on the same DEXA scanner.
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MRI hip
Cross-sectional imaging of the hip — for occult fracture, marrow oedema and joint disease.
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In practice, in London
What bone densitometry scanning looks like on the ground in London
With bone densitometry scanning, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. Public provision for bone densitometry scanning is competent but constrained by capacity. Private London clinics tend to have shorter diaries and longer appointment slots, so you get the same specialists with more time. For people who’ve been going round in circles with primary care, that first proper conversation is often what shifts things.
A private bone densitometry scanning pathway in London usually looks like this: an initial consultation, any diagnostics booked at a nearby facility (most within Zone 1 or 2), and a written report sent to you and your GP within a few days. The consultants we work with hold NHS posts alongside their private lists, which keeps the standards consistent across both settings. For bone densitometry scanning specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
Honesty about expectations is part of the job. A private bone densitometry scanning appointment in London won’t change the underlying medicine — the guidelines, the consultants, and the equipment are largely the same as on the NHS. What it changes is speed, continuity, and the amount of time you get to actually talk through the findings. Everyone we route to is GMC-registered and works within CQC-regulated facilities.
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